Process of transferring gases and vapors



Feb. 21, 1928;

G. E. FOX

PROCESS OF TRANSFERRING GASES AND VAPORS Filgd D60. 9. 1925 TER anvewto'z GISOHQE azn m WWW.

Patented eb. 21, 1928,.

UNITED STATES PATENT OFFICE.

GEORGE E. FOX, 01? ELIZABETH, NEW JERSEY, ASSIGNOR TO STANDARD OIL DEVELOP- MENT COMPANY, A CORPORATION OF DELAWARE.

PROCESS OF TRANSFERRING GASES-AND VAPORS.

Application filed December 9, 1925. Serial No. 74,256.

This invention relates'to improvements in the transfer of gaseous or vaporous hydrocarbons and comprisesthe use of relatively high pressure hydrocarbon gas or vapor as the transfer agent. For brevity in the subsequent description and in the claims, reference will be made .to hydrocarbon gas, it being understood that this term as used herein covers hydrocarbon vapors also, whether associated or not with liquid hydrocarbons.

The invention will be fully understood from the following description, taken in connection with the accompanying drawing, in

'which I Fig. 1 is a vertical section of one form of injection apparatus; and

, Fig. 2 is a diagrammatic side elevation of hydrocarbon cracking equipment, in which my improved transfer process is utilized.

perature.

Referring first to Fig. 1, reference numeral 1 denotes a conduit or pipe of relatively large diameter, having a constriction 2' therein. A pipe 3 of smaller diameter. enters the conduit .1 and has its delivery end 4 turned in the directionof the flow of gas through the conduit. The' pipe 3 is con-' nected with a supply of hydrocarbon gas under pressure, for'example a gas compressor, an oil refinery high line receiving hig pressure gas from pressure stills and the like, or other suitable source. The conduit 1 is connected to a source of the low pressure gas which it is desired to transfer. The gas may be allowed to expand adi'abatically from the pipe 3, or heating means may be provided to counteract the cooling incident to expansion or to raise the gas to any desired tem- In Fig. 2 there is c illustrated cracking equipment, comprising a heating coil 5 arranged in a suitable furnace setting 6, and a digesting chamber or soaking drum 7. The drum may have thermal insulation 8 or it may be j acketed with flue gases or otherwise protected against substantial temperature loss. A pipe 9connects the coil and drum. In this pipe an injection device or nozzle 10, having a constriction 11, is installed.

A compressor 12 forwards gas under high pressure through pipe 13 to the injection device 10. A coil. 14 may be included in the ipe 13 and arranged in a furnace 15, so that the gas may be supplied at the desired high temperature. The hydrocarbon gas to be injected may be obtained from any suitable source. When the system is in full operation, suflicient gas for injection pur-' withdrawn to storage or other suitable disposition, through pipe 17.

The bubble tower may have a cooling coil 20 in its upper portion. A collecting pan 21- receives condensate which is withdrawn through pipe 22 for return to the system or for other suitable disposition. for drawing off residuum is connected to the lower portion of the tower. -A pipe 24 conveys the product from the soaking drum 7 to the lower portion of the tower. A pressureregulating valve 25 is installed in the pipe 24. Another, pressure-regulating valve 26 may be placed in a vapor line 27 leading from the tower;. v

The following example is illustrative of one embodimentv of my invention: The oil to h be cracked is' 'fed into the coil 5 which is maintained at a temperature of about 680 to 700 F. and under a pressure of less than 50 lbs. per square inch, preferably about 25 A pipe 23 lbs. per square-inch. Under these conditions a substantial proportion of the oil is vaporized in the coil; The rate of flow through the coil is preferably so rapid ,that little, if any, cracking and .coke formation take place therein. The oil passes from the coil through pipe 9 into the injection device 10. Gas under high pressure, preferably about 1000 lbs. per square inch, is supplied from the compressor 12. Mingling with this gas in the injection device, the low pressure vapors and liquids from the heating coil 5 are carried through the constricted passage 11 and into the drum 7' in which a pressure of about 350 lbs. is produced. In this way I am able to increase greatlyv the pressure ,upon the vapors issuing from the heating coil, without the use of a pump. As is well known, difiiculties are frequently encoun-- tered when using pumps for transferring oil under high pressure and temperature. The momentary constriction of the gas flow is an important feature of-the invention, as

by it there is obtained what I believe to be an actual compressive effect upon the low pressure vapor.

The high pressure gas is preferably heated to about 900 F. in the -heater 15. In the valve 25 to any desired extent. Preferably the bubble tower. is operated at 60 lbs. pressure or. less, and this pressure may bacontrolled by the valve 26. The vaporsare taken oil from the upper portion of the tower for condensation, and the residuum-or tar is drawn oil from the bottom as required. i

The use of my invention permits the avoidance 'of mechanical pumps for they transfer of oil from heating coils to digesting chambers. Gas injection in the manner described is a reliable and economical method for producing the desired pressure I in a digesting chamber operated in connectlon with a vapor phase or semi-vapor phase heating coil.

My invention is not restricted inits application to the particular apparatus just described, It may be used in a variety of other connections, for example in accelerating the flow of gas through a refinery. low line receiving gas at low pressure, for transferring still. vapors through a bubble tower, or for other purposes.

'35 The procedures described are illustrative of preferred forms of the invention, but various modifications may be made withinthc scope of the appended claims, in which it is my intention to. claim all novelty inherent in the invention as broadly as the prior art permits. 1

I claim:

1. Process of transferring hydrocarbon vapors from a heating coil to a digesting zone in which conversion takes place, comprising passing the vapors from the coil at relatively low pressure into a conduit, injecting into the conduit in the direction of travel a stream of gas at high pressure, constricting the flow of the vapors and gas, and then allowing the stream to expand into the digesting zone under a pressure materially higher than that prevailing in the coil.

2. Process of transferring hydrocarbon vapors from a heating coil to an enlarged digesting zone in which conversion takes place, comprising passing into a conduit the product from the coil partly in vapor phase and at a pressure not in substantial excess of 50 lbs. per square inch, injecting into the conduit in the direction of travel a stream of gas ata pressure approximating 1000 lbs. per square inch, constricting the flow of the gas for a brief period, and then allowing expansion into the enlarged chamber, whereby the low pressure vapors are forced into such chamber and subjected to a pressure of the order of 350 lbs. per square inch therein.

GEORGE E. FOX. 

